Published in Mathematical Notes
We consider the problem of constructing upper bounds for the expectation of the norm of a vector uniformly distributed on the Euclidean unit sphere.
Published in Open Astronomy
The intersections between a spherical shell and the faces of Voronoi polyhedrons are numerically evaluated. The nodes of these intersections are the points that share the same distances from three nuclei. The nodes are assumed to be the places where we will find clusters of galaxies. The cosmological environment is given by the coupling between the...
Published in Semiconductors
AbstractThe local structure of film samples of the chalcogenide glassy semiconductors Se95As5 and Se95As5(EuF3)x (x = 0.01–1 at %) are studied by X-ray diffraction and Raman scattering. The “quasiperiod” of the structure, the correlation length, the structural elements, and the chemical bonds, which form the amorphous matrix of the investigated mat...
Published in Semiconductors
AbstractWe report the results of systematic Raman spectroscopy studies of AlxGa1 –xN (x ~ 0.75) layers grown using plasma-assisted molecular beam epitaxy at various stoichiometric conditions and growth fluxes. The high-intensity asymmetric low-frequency peak obeying Bose statistics is discovered in Raman spectra of the layers grown by temperature-m...
Published in Semiconductors
AbstractDuring the powerful picosecond optical pumping of a thin (~1 μm) GaAs layer, a stimulated intense (up to 1 GW/cm2) picosecond emission arises. It is found that the characteristic picosecond relaxation time τr of the emission and of the carrier density increase with an increase of the diameter of the pump pulse for a fixed density of the pum...
Published in Semiconductors
AbstractThin AlN nanofilms are produced by reactive ion-plasma deposition onto GaAs(100) substrates misoriented with respect to the 〈100〉 direction to different degrees. It is shown that growth on substrates misoriented with respect to the 〈100〉 direction to different degrees results in the formation of AlN films with different phase compositions a...
Published in Semiconductors
AbstractAttenuated total reflection infrared spectroscopy is used to determine the free charge carrier concentration in arrays of silicon nanowires with characteristic transverse sizes of 50–100 nm and a length of the order of 10 μm formed on lightly doped crystalline p-type silicon by metal-assisted chemical etching and subjected to the additional...
Published in Semiconductors
AbstractThe Raman-scattering technique is used to analyze the structural quality of bulk AlN crystals grown by sublimation on SiC and AlN seeds. Growth on SiC seeds is conducted with retention of the SiC seed during growth (type 1) and with total evaporation of the SiC seed (type 2). Growth on AlN seeds is conducted in tungsten containers with no g...
Published in Semiconductors
AbstractThe accumulation of structural damage in GaN under irradiation with accelerated F and Ne ions with energies of 1.3 and 3.2 keV/amu is investigated. It is shown that chemical effects during implantation of fluorine ions within the doses under consideration do not noticeably affect the formation of stable structural damage both in the bulk an...
Published in Semiconductors
AbstractGaInPAs/InP heterostructures grown by metalorganic chemical vapor-phase deposition at a temperature of 600°C and pressure of 0.1 bar are investigated. The thicknesses of the grown GaInAsP layers amount to about 1 μm. For Ga1 –xInxP1 –yAsy solid solutions with average compositions of x = 0.77–0.87 and y = 0.07–0.42, the variation in the cont...
